Thunder King Rai-Oh (Official Rulings)

-Sending this card to the Graveyard is a cost to activate the effect which negates Special Summons. This effect does not target.

-The effects of "Thunder King Rai-Oh", "Black Horn of Heaven", "Solemn Judgment", and similar cards can only be activated when a monster Special Summons itself without starting a Chain, such as when a Special Summon monster Special Summons itself.Example: The effect of "Thunder King Rai-Oh" can negate the Special Summon of "Cyber Dragon", "Dark Armed Dragon", and "Endymion, the Master Magician".Example: The effect of "Thunder King Rai-Oh" can negate a Synchro Summon" and the Special Summon of "Gladiator Beast Gyzarus" from the Extra Deck.

-The effects of "Thunder King Rai-Oh", "Black Horn of Heaven", "Solemn Judgment", and similar cards cannot negate a Special Summon by another card effect.Example: Cards like "Thunder King Rai-Oh" cannot negate the Special Summon by the effects of "Monster Reborn" or "Polymerization". However, "Solemn Judgment" can also negate the activation of a Spell/Trap Card, so it can negate the activation of "Monster Reborn" or "Polymerization" itself.

-The effects of "Thunder King Rai-Oh", "Black Horn of Heaven", "Solemn Judgment", and similar cards cannot negate a Special Summon which occurs during the resolution of an effect which activates.Example: When Battle Damage is inflicted, the effect of "Gorz the Emissary of Darkness" which Special Summons it activates. Thus, you cannot negate this with the effect of "Thunder King Rai-Oh".Example: Monsters in the hand or Graveyard are removed from play to activate the effects which Special Summon "Dark Simorgh". Thus, you cannot negate this with the effect of "Thunder King Rai-Oh".

-"Thunder King Rai-Oh" and similar cards can negate a Synchro Summon. The card is activated after sending the Synchro Material Monsters to the Graveyard, but before the Synchro Summon is successful.

-"Thunder King Rai-Oh" negates Special Summons the same way that "Solemn Judgment", "Horn of Heaven", and "Black Horn of Heaven" negate Special Summons. You can only use the effect against a Special Summon which does not use a Chain Link. You cannot use the effect when a monster is Special Summoned during the resolution of another card.

-"Thunder King Rai-Oh"'s effect activates after the Summon has been declared, but before the Summon is successful.On Negating the Summon of Specific Cards

-Backup Warrior: If the Special Summon of "Backup Warrior" is negated by an effect like that of "Solemn Judgment" or "Thunder King Rai-Oh", then you still cannot Synchro Summon during the same turn. If the Synchro Summon of a Synchro Monster is negated, then you still cannot Special Summon "Backup Warrior" during the same turn.

-Endymion, the Master Magician: If "Endymion, the Master Magician" Special Summons itself from the hand or Graveyard by removing six Spell Counters from "Magical Citadel of Endymion", then "Thunder King Rai-Oh"/"Black Horn of Heaven"/etc can negate the Special Summon of and destroy "Endymion, the Master Magician".

-Lava Golem: When your opponent Special Summons "Lava Golem" to your field, you can activate "Thunder King Rai-Oh"'s effect to negate the Special Summon, as long as "Lava Golem" didn't Tribute "Thunder King Rai-Oh".

-Machina Fortress: Effects like "Solemn Judgment" and the effect of "Thunder King Rai-Oh" may be activated if "Machina Fortress" is Special Summoning itself by its effect, to negate the Special Summon of "Machina Fortress".On Not Adding Cards to Hands

-When "Thunder King Rai-Oh" is face-up on the field, you cannot activate "Terraforming", "Reinforcement of the Army", etc.

-While "Thunder King Rai-Oh" is on the field, you can still remove from play cards from your deck and you can still add cards to your hand which have been removed from play, so you can still activate "Gold Sarcophagus"/"Different Dimension Capsule"/etc, and afterwards the card will be added to your hand.

-If the effect of "Thunder King Rai-Oh" which prevents cards from being added to the hand from the Deck except by drawing is active, then players may still add cards to their hands by drawing them from the Deck. Thus, "Pot of Avarice" may still be activated while "Thunder King Rai-Oh" is on the field, and the player will still draw cards from his Deck.Versus Specific Cards

-Conscription: "Conscription" can be activated while "Thunder King Rai-Oh" is face-up on the field. If the card would be added to the Hand, then it is instead sent to the Graveyard.

-Crystal Seer: When resolving the effect of "Crystal Seer", if "Thunder King Rai-Oh" is face-up on the field, then the card to be added to the hand is instead sent to the Graveyard. The other card is returned to the bottom of the deck normally.

-Cyber Jar: When resolving the effects of "Magical Merchant" and "Cyber Jar", if "Thunder King Rai-Oh" is on the field, you send to the Graveyard the card(s) which would be added to your hand.

-Elemental HERO Stratos: If "Elemental HERO Stratos" is Summoned while "Thunder King Rai-Oh" is face-up on the field, then you cannot choose to activate the effect which adds a "HERO" monster from your deck to your hand. However, you can choose to activate the effect which destroys Spell/Trap cards.

-Emblem of Dragon Destroyer: You can activate "Emblem of Dragon Destroyer", etc, while "Thunder King Rai-Oh" is face-up on the field. When resolving the effect, if "Thunder King Rai-Oh" is on the field, then you can only add a "Buster Blader" from your Graveyard to your hand.

-Magical Merchant: See above; listed under "Cyber Jar".

-Painful Choice: You cannot activate "Painful Choice" when "Thunder King Rai-Oh" is face-up on the field. If "Thunder King Rai-Oh" is on the field when "Painful Choice" resolves, the selected card is sent to the Graveyard.

Mentions in Other Rulings:

-Dimension Fortress Weapon: If a card needs to be sent from the Deck to the Graveyard because of a card combination that renders the usual resolution impossible, that card is still sent to the Graveyard even if “Dimension Fortress Weapon” is on the field.Example #1: If “Dimension Fortress Weapon” is on the field and you activate “Conscription”, and pick up a monster that could be Normal Summoned, but your Monster Card Zones are full, the monster is sent to the Graveyard.Example #2: The same is true for extra monsters from “Enchanting Fitting Room” that cannot be Summoned due to lack of available Monster Card Zones.Example #3: “Crystal Seer” is flipped face-up while “Thunder King Rai-Oh” is on the field.

-Machina Fortress: You can negate this Summon with “Thunder King Rai-Oh” or “Solemn Judgment.”

-Morphtronic Forcefield: You cannot activate “Morphtronic Forcefield” if “Thunder King Rai-Oh” is on the field. If an effect is chained to “Morphtronic Forcefield” that Summons “Thunder King Rai-Oh”, you will not be able to add a “Morphtronic” monster to your hand, but “Morphtronic Forcefield” will still negate the Spell or Trap Card that it was chained to.

-Power Tool Dragon: You cannot activate “Power Tool Dragon’s” effect while “Thunder King Rai-Oh” is active. If you activate the effect, and an effect is chained which places “Thunder King Rai-Oh” on the field, proceed with “Power Tool Dragon’s” effect but the 1 picked card goes to the Graveyard instead of your hand.